Optical disk unit

1. An optical disk unit comprising: a light source irradiating a light beam on a recordable optical disk; rotationally driving means for rotating the optical disk; setting means for presetting a value 1 which prescribes an optimum recording pulse width of the light source for a case where the optical disk is rotated at a predetermined linear velocity on a track located at a predetermined radial position on the optical disk, and an optimum power ratio P of an extra pulse at a leading portion of the recording pulse where power is increased; test write means for carrying out a test write a predetermined number of times prior to recording, on the track located at the predetermined radial position on the optical disk, by driving the light source at a recording power which differs for each step, while rotating the optical disk by the rotationally driving means at the predetermined linear velocity, using the value 1 which prescribes the optimum recording pulse width the optimum power ratio P of the extra pulse which are preset by the setting means; reference optimum recording power determination means for reproducing data recorded by the test write carried out by the test write means, and determining an optimum recording power Pwo based on characteristic values of the reproduced data; recording rotation control means for rotating the optical disk by the rotationally driving means at a predetermined number of revolutions when recording information; light emission waveform updating computation means for successively calculating a value 1 (v) which prescribes the recording pulse width, a power ratio A P(v) and an optimum recording power Pwo(v), depending on an arbitrary linear velocity v at a recording target track which is to be recorded, by adding corrections dependent on the arbitrary linear velocity v with respect to the value 1 which prescribes the optimum recording pulse width when recording the information, the power ratio P and the optimum recording power Pwo which is determined by the reference optimum recording power determination means; and recording light source control means for recording the information while controlling a light emission waveform of the light source based on the value 1 (v) which prescribes the recording pulse width, the power ratio P(v) and the optimum recording power Pwo(v) which are successively calculated by the light emission waveform update computation means.

2. The optical disk unit as claimed in claim 1 , further comprising: judging means for judging whether or not the optimum recording power Pwo(v) calculated by the light emission waveform update computation means depending on the arbitrary linear velocity v on the track reaches a predetermined upper limit value of an output power of the light source, said recording rotation control means switching rotation to rotate the optical disk by the rotationally driving means at a constant linear velocity in a track region in which the judging means judges that the optimum recording power Pwo(v) reaches the predetermined upper limit value of the output power of the light source.

3. The optical disk unit as claimed in claim 1 , further comprising: manufacturer judging means for judging a manufacturer of the optical disk based on an identification code prerecorded on the optical disk, said light emission waveform updating computation means calculating the value 1 (v) which prescribes the recording pulse width, the power ratio P(v) and the optimum recording power Pwo(v), depending on the arbitrary linear velocity v and coefficients which are preset for each manufacturer judged by the manufacturer judging means.

4. The optical disk unit as claimed in claim 3 , wherein said manufacturer judging means further judges a type of the optical disk, and said light emission waveform updating computation means uses for the calculation values which are obtained by multiplying constants to corresponding ones of the coefficients depending on the type of the optical disk judged by said manufacturer judging means.

5. An optical disk unit for recording information on a recordable optical disk which has a recording surface divided into a plurality of zones in a radial direction thereof, by rotating the optical disk at a rotational velocity which is different for each zone so that a linear velocity within each zone is approximately constant, said optical disk unit comprising: a light source irradiating a light beam on the optical disk; rotationally driving means for rotating the optical disk; setting means for presetting a value 1 which prescribes an optimum recording pulse width of the light source for a case where the optical disk is rotated at a predetermined linear velocity on a track located at a predetermined radial position on the optical disk, and an optimum power ratio P of an extra pulse at a leading portion of the recording pulse where power is increased; test write means for carrying out a test write a predetermined number of times prior to recording, on the track located at the predetermined radial position on the optical disk, by driving the light source at a recording power which differs for each step, while rotating the optical disk by the rotationally driving means at the predetermined linear velocity, using the value 1 which prescribes the optimum recording pulse width the optimum power ratio P of the extra pulse which are preset by the setting means; reference optimum recording power determination means for reproducing data recorded by the test write carried out by the test write means, and determining an optimum recording power Pwo based on characteristic values of the reproduced data; recording rotation control means for rotating the optical disk by the rotationally driving means at a rotational velocity which is different for each zone so that a predetermined linear velocity is approximately obtained within each zone when recording information; light emission waveform updating computation means for successively calculating a value 1 (v) which prescribes the recording pulse width, a power ratio P(v) and an optimum recording power Pwo(v), depending on an arbitrary linear velocity v at a recording target zone which is to be recorded, by adding corrections dependent on the arbitrary linear velocity v with respect to the value 1 which prescribes the optimum recording pulse width when recording the information, the power ratio P and the optimum recording power Pwo which is determined by the reference optimum recording power determination means; and recording light source control means for recording the information while controlling a light emission waveform of the light source based on the value 1 (v) which prescribes the recording pulse width, the power ratio P(v) and the optimum recording power Pwo(v) which are successively calculated by the light emission waveform update computation means.

6. The optical disk unit as claimed in claim 5 , further comprising: judging means for judging whether or not the optimum recording power Pwo(v) calculated by the light emission waveform update computation means depending on the arbitrary linear velocity v on the track reaches a predetermined upper limit value of an output power of the light source, said recording rotation control means switching rotation to rotate the optical disk by the rotationally driving means at a linear velocity with which the predetermined upper limit value becomes the optimum recording power Pwo(v) in a recording zone region in which the judging means judges that the optimum recording power Pwo(v) reaches the predetermined upper limit value of the output power of the light source.

7. The optical disk unit as claimed in claim 5 , further comprising: manufacturer judging means for judging a manufacturer of the optical disk based on an identification code prerecorded on the optical disk, said light emission waveform updating computation means calculating the value 1 (v) which prescribes the recording pulse width, the power ratio P(v) and the optimum recording power Pwo(v), depending on the arbitrary linear velocity v and coefficients which are preset for each manufacturer judged by the manufacturer judging means.

8. The optical disk unit as claimed in claim 7 , wherein said manufacturer judging means further judges a type of the optical disk, and said light emission waveform updating computation means uses for the calculation values which are obtained by multiplying constants to corresponding ones of the coefficients depending on the type of the optical disk judged by said manufacturer judging means.

9. An optical disk unit comprising: a light source irradiating a light beam on a rewritable optical disk; rotationally driving means for rotating the optical disk; setting means for presetting an optimum peak pulse width 2 at a leading portion of multi-recording pulses of the light source and an OFF-pulse width xn at a last portion of the multi-recording pulses for a case where the optical disk is rotated at a predetermined linear velocity on a track located at a predetermined radial position on the optical disk; test write means for carrying out a test write a predetermined number of times prior to recording, on the track located at the predetermined radial position on the optical disk, by driving the light source at a recording power which differs for each step, while rotating the optical disk by the rotationally driving means at the predetermined linear velocity, using the peak pulse width 2 and the OFF-pulse width xn which are preset by the setting means; reference optimum recording power determination means for reproducing data recorded by the test write carried out by the test write means, and determining an optimum recording power Pwo based on characteristic values of the reproduced data; recording rotation control means for rotating the optical disk by the rotationally driving means at a predetermined number of revolutions when recording information; light emission waveform updating computation means for successively calculating a peak pulse width 2 (v), an OFF-pulse width xn(v) and an optimum recording power Pwo(v), depending on an arbitrary linear velocity v at a recording target track which is to be recorded, by adding corrections dependent on the arbitrary linear velocity v with respect to the peak pulse width 2 , the OFF-pulse width xn and the optimum recording power Pwo which is determined by the reference optimum recording power determination means; and recording light source control means for recording the information while controlling a light emission waveform of the light source based on the peak pulse width 2 (v), the OFF-pulse width xn(v) and the optimum recording power Pwo(v) which are successively calculated by the light emission waveform update computation means.

10. The optical disk unit as claimed in claim 9 , further comprising: judging means for judging whether or not the optimum recording power Pwo(v) calculated by the light emission waveform update computation means depending on the arbitrary linear velocity v on the track reaches a predetermined upper limit value of an output power of the light source, said recording rotation control means switching rotation to rotate the optical disk by the rotationally driving means at a constant linear velocity in a track region in which the judging means judges that the optimum recording power Pwo(v) reaches the predetermined upper limit value of the output power of the light source.

11. The optical disk unit as claimed in claim 9 , further comprising: manufacturer judging means for judging a manufacturer of the optical disk based on an identification code prerecorded on the optical disk, said light emission waveform updating computation means calculating the peak pulse width 2 (v), the OFF-pulse width xn(v) and the optimum recording power Pwo(v), depending on the arbitrary linear velocity v and coefficients which are preset for each manufacturer judged by the manufacturer judging means.

12. The optical disk unit as claimed in claim 11 , wherein said manufacturer judging means further judges a type of the optical disk, and said light emission waveform updating computation means uses for the calculation values which are obtained by multiplying constants to corresponding ones of the coefficients depending on the type of the optical disk judged by said manufacturer judging means.

13. An optical disk unit for recording information on a rewritable optical disk which has a recording surface divided into a plurality of zones in a radial direction thereof, by rotating the optical disk at a rotational velocity which is different for each zone so that a linear velocity within each zone is approximately constant, said optical disk unit comprising: a light source irradiating a light beam on the optical disk; rotationally driving means for rotating the optical disk; setting means for presetting a peak pulse width 2 at a leading portion of multi-recording pulses of the light source and an OFF-pulse width xn at a last portion of the multi-recording pulses for a case where the optical disk is rotated at a predetermined linear velocity on a track located at a predetermined radial position on the optical disk; test write means for carrying out a test write a predetermined number of times prior to recording, on the track located at the predetermined radial position on the optical disk, by driving the light source at a recording power which differs for each step, while rotating the optical disk by the rotationally driving means at the predetermined linear velocity, using the peak pulse width 2 and the OFF-pulse width xn which are preset by the setting means; reference optimum recording power determination means for reproducing data recorded by the test write carried out by the test write means, and determining an optimum recording power Pwo based on characteristic values of the reproduced data; recording rotation control means for rotating the optical disk by the rotationally driving means at a rotational velocity which is different for each zone so that a predetermined linear velocity is approximately obtained within each zone when recording information; light emission waveform updating computation means for successively calculating a peak pulse width 2 (v), an OFF-pulse width xn(v) and an optimum recording power Pwo(v), depending on an arbitrary linear velocity v at a recording target zone which is to be recorded, by adding corrections dependent on the arbitrary linear velocity v with respect to the peak pulse width 2 , the OFF-pulse width xn and the optimum recording power Pwo which is determined by the reference optimum recording power determination means; and recording light source control means for recording the information while controlling a light emission waveform of the light source based on the peak pulse width 2 (v), the OFF-pulse width xn(v) and the optimum recording power Pwo(v) which are successively calculated by the light emission waveform update computation means.

14. The optical disk unit as claimed in claim 13 , further comprising: judging means for judging whether or not the optimum recording power Pwo(v) calculated by the light emission waveform update computation means depending on the arbitrary linear velocity v on the track reaches a predetermined upper limit value of an output power of the light source, said recording rotation control means switching rotation to rotate the optical disk by the rotationally driving means at a linear velocity with which the predetermined upper limit value becomes the optimum recording power Pwo(v) in a recording zone region in which the judging means judges that the optimum recording power Pwo(v) reaches the predetermined upper limit value of the output power of the light source.

15. The optical disk unit as claimed in claim 13 , further comprising: manufacturer judging means for judging a manufacturer of the optical disk based on an identification code prerecorded on the optical disk, said light emission waveform updating computation means calculating the peak pulse width 2 (v), the OFF-pulse width xn(v) and the optimum recording power Pwo(v), depending on the arbitrary linear velocity v and coefficients which are preset for each manufacturer judged by the manufacturer judging means.

16. The optical disk unit as claimed in claim 15 , wherein said manufacturer judging means further judges a type of the optical disk, and said light emission waveform updating computation means uses for the calculation values which are obtained by multiplying constants to corresponding ones of the coefficients depending on the type of the optical disk judged by said manufacturer judging means.